Bad exposures not bad luck cause cancers

Workplace, environmental and other ‘extrinsic’ exposures are the cause of up to 90 per cent of cancers, researchers have concluded.

The study by a team at Stony Brook University in the US was prompted by a heavily criticised paper in the journal Science which in January 2015 claimed ‘bad luck’ was behind most cancers.

The new research “found quantitative evidence proving that extrinsic risk factors, such as environmental exposures and behaviours weigh heavily on the development of a vast majority (approximately 70 to 90 per cent) of cancers.”

Song Wu, lead author of the paper and assistant professor in the Department of Applied Mathematics and Statistics, Stony Brook University, said; “Many scientists argued against the ‘bad luck’ or ‘random mutation’ theory of cancer but provided no alternative analysis to quantify the contribution of external risk factors.” He added: “Our paper provides an alternative analysis by applying four distinct analytic approaches.”

The finding, published online in the journal Nature on 16 December 2015, concluded cancers are overwhelmingly the result of external risk factors and not bad luck.

The authors used four separate research techniques, employing both data- and model-driven quantitative analyses to reach their conclusion. These analyses discovered “collectively and individually that most cancers are attributed largely to external risk factors, with only 10-to-30 per cent attributed to random mutations, or intrinsic factors.”

Co-author Professor Yusuf Hannun, director of Stony Brook University Cancer Center, concluded that their overall approach “provides a new framework to quantify the lifetime cancer risks from both intrinsic and extrinsic factors, which will have important consequences for strategising cancer prevention, research and public health.”